nsw_dems
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| nsw_dems [2021/02/10 14:03] – bushwalking | nsw_dems [2021/02/17 20:46] – bushwalking | ||
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| ====== Managing large DEMs ====== | ====== Managing large DEMs ====== | ||
| - | ===== Downloading data ===== | + | ===== Intro ===== |
| While data can be downloaded in an ad hoc manner, if you are regularly processing DEMs, it is better to have the DEM tiles already downloaded. | While data can be downloaded in an ad hoc manner, if you are regularly processing DEMs, it is better to have the DEM tiles already downloaded. | ||
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| + | Once downloaded, pre-process the tiles into GeoTIFFs, build a virtual raster for each 1:100k grid square. You can then build a virtual raster of virtual rasters! | ||
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| + | ===== Downloading data ===== | ||
| Download tiles by 1:100k map area, which is 0.5 x 0.5 degree squares. Each 1:100k map area ranges from around 2GB to 6GB of data, depending on the number of 2m DEMs vs 1m DEMs, and other factors. | Download tiles by 1:100k map area, which is 0.5 x 0.5 degree squares. Each 1:100k map area ranges from around 2GB to 6GB of data, depending on the number of 2m DEMs vs 1m DEMs, and other factors. | ||
nsw_dems.txt · Last modified: 2023/11/23 15:01 by bushwalking